Ventilators are used to provide a breathing gas to a patient who is unable to breathe sufficiently without assistance. In modern medical facilities, pressurized air and oxygen sources are often available from wall outlets. Accordingly, ventilators may provide pressure regulating valves connected to centralized sources of pressurized air and pressurized oxygen. The pressure regulating valves function to regulate flow so that respiratory air having a desired concentration of oxygen is supplied to the patient at desired pressures and rates. Ventilators capable of operating independently of external sources of pressurized air and oxygen are also available.
A typical ventilator has a number of settings that can be used to control parameters according to which breathing gas is supplied to a patient. In order to facilitate the entry of ventilator settings by a user, some ventilators have provided a standby mode. In a conventional standby mode, a user may set operating parameters, without breathing gas being provided at the supply port of the ventilator. Accordingly, in order to provide breathing gas to a patient, the user must remember to exit the standby mode and enter a normal operating mode. If this is not done, no benefit is provided to the patient, as no breathing gas is supplied in a conventional standby mode. Accordingly, such standby modes may be considered unsafe, as the ventilator may appear to be on, even though no breathing gas is being supplied to the patient.
After ventilation of a patient has begun, a disconnect mode can be entered if the ventilator determines that the patient has become disconnected. In the disconnect mode, an alarm will typically sound if the disconnect state has persisted for some threshold period of time. Because of this, a medical professional may need to repeatedly silence the disconnect alarm, for example while performing procedures that require the disconnection of the patient from the ventilator. Moreover, in such situations, turning off the ventilator is not an attractive option, because there typically is a ventilator boot time or delay between powering on the ventilator and obtaining a breathing gas from the ventilator. In addition, patient settings will typically need to be reentered after the ventilator has been powered off. Although some ventilators provide the option of entering a standby mode during procedures that require disconnecting the patient, the use of such a conventional standby mode is not particularly safe. In particular, no breathing gas is supplied to the patient if the user forgets to restart normal ventilation after entering the standby mode, even if the patient is connected to the ventilator.